A conventional tube-shaped flexible member has a cylindrical wall which is axially attached to a roll-off piston. All air springs incorporating this type of flexible member function only when they are charged with pressure. A roll off of the flexible member on the roll-off piston is not possible in the pressureless state. A pressureless state can, for example, occur during maintenance work. If a vehicle is raised on a lift, the air springs are stretched because they are relieved of the weight of the vehicle and are pulled by the weight of the axles. If the vehicle is then again set down with pressureless air springs, an uncontrollable collapse takes place with conventional tubular-shaped flexible members and this collapse can lead to damage or even destruction of the air spring.
European patent publication 0,548,581 discloses an air spring having a tubular-shaped flexible member wherein the flexible member is not clamped axially as usually but is radially aligned as best shown, for example, in FIGS. 1 and 4 of this publication. The radial alignment of the flexible member attachment affords the advantage that only a 90° redirection is required for the roll-off operation. The exit out of the clamped region transversely to the axis viewed by itself is not a condition precedent for a pressureless roll off. Viewed further, FIG. 1 of European patent publication 0,548,581 does very effectively illustrate the subject matter (pressureless: solid lines; charged with pressure: broken lines). In the pressureless state (solid lines), there results a sharp bend of the flexible member extending radially out from the attachment. A trouble-free roll off of the flexible member on the piston wall is not ensured when there is a pressureless collapse of the air spring.